[theora] NHW Project - improvement of -l7 quality setting - more precision

[Raphael Canut]

Hello,

I have corrected an error in the new processing for -l7 quality
setting.This setting is better now, more precision.

Update at: http://nhwcodec.blogspot.com/

I think now -h3 to -l7 quality settings are validated, and the NHW Project
has reached now a good demo version (just lacks very high compression, I'm
working on it...).

Any opinion on this version is very welcome!

Cheers,
Raphael